Perl hash add values - perl

Question

I am trying to push values into hash. I want to add the values under 'par3'.
e.g.
$VAR1 = { 'obj1' => ['par1',
'par2',
'par3' => ['par4','par5','par6',....]]}
I should also be able to add elements into 'par3' in case 'obj1'-'par1'-'par2'-'par3' matches.
So far I have this, but I can't figure out how can I add "the second level" under 'par3':
push #{$a{$obj}},$par1,$par2,$par3

Answer 1

[ ... ] is a reference to an array. Array elements are scalars. So it is not possible to directly have the structure you seem to be requesting (ie. the par3 => [ ... ] pseudocode from your question). See perldsc
It's not obvious what you are trying to do but a couple of possible ideas might be to use a reference to a hash, or to replace the array with a hash:
use Data::Dumper;
$Var2a = {
'obj1' => [
'par1',
'par2',
{ 'par3' => undef, }
],
};
push #{ $Var2a->{obj1}[2]{par3} }, 'par4', 'par5', 'par6';
print Dumper $Var2a;
$Var2b = {
'obj1' => {
'par1' => undef,
'par2' => undef,
'par3' => undef,
},
};
push #{ $Var2b->{obj1}{par3} }, 'par4', 'par5', 'par6';
print Dumper $Var2b;

Answer 2

I think you want to add children to par3. As such, I think you want pars to have children. If so, you need a different data structure.
# Ordered
my $obj1 = [
{ name => 'par1', children => [ ] },
{ name => 'par2', children => [ ] },
{ name => 'par3', children => [
{ name => 'par4', children => [ ] },
{ name => 'par5', children => [ ] },
{ name => 'par6', children => [ ] },
] },
];
or
# Unordered
my $obj1 = {
par1 => { },
par2 => { },
par3 => {
par4 => { },
par5 => { },
par6 => { },
},
};
To append par7 to par3's children, you would use
# Ordered
use List::Util qw( first );
my $par7 = { name => 'par7', children => [ ] };
my $par3 = first { $_->{ name } eq 'par3' } #$obj1
or die( "par3 not found" );
push #{ $par3->{ children } }, $par7;
or
# Unordered
$obj1->{ par3 }{ par7 } = { };